Apparatus for dehumidifying air, etc.



Aug. 5, 1930. A. K. SMITH APPARATUS FOR DEHUMIDIFYING AIR, ETC

Filed Aug. 26; 1926 2 Sheets-Sheet I INVENTOR. 0/601 /Z. 62771771 v 90 A TTORNEYS.

Aug. 5, 1930.

A. K. SMITH APPARATUS FOR DEHUMIDIFYING AIR, ETC

Filed Aug. 26, 1926 2 SheetsSheet 2 INVENTOR.

ATTORNEY Patented Aug. 5, 1930 UNITED STATES PATENT OFFICE ALBERT IKELVIN SMITH, OF MIDLAND, MICHIGAN. ASSIGNOR TO THE DOW CHEMICAL COMPANY, OF MIDLAND, MICHIGAN, A CORPORATION OF MICHIGAN APPARATUS FOB DEHUMIDIFYING AIR, ETC.

Application filed August 26, 1926. Serial No. 131.802.

This invention relates to the-dehumidify-- ing of gases and more particularly the treat ing of air or other gases by moisture-absorbent agents, and it is among the obects of the invention to provide a construction and procedure for the eflicient-application of moisture-absorbing materials such as calcium-chloride and the like, in such use. Other objects and advantages will appear as the description proceeds.

To the accomplishment of the foregoing I and related, ends, the invention, then, consists of the features hereinafter fully described, and particularly pointed out in the claims, the annexed drawing and the following description setting forth but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings Fig. 1 and Fig. 1A together shown in vertical section one form of embodiment of my invention: Fig. 2 is a vertical sectional View of a modification; Fig. 3 is an enlarged transverse section takenon a plane indicated by the line III-III, Fig. 2; and Fig. 4 is a vertical sectional view showing another modification.

In its general aspects, the invention contemplates the provision of a moisture-absorbing agent in such arrangement as to allow progressive supply of replenishing charges, and preferably counter-currently to the flow of gas treated.

A container 1,- usually of greater length than diameter, has an inlet 2 and an outlet 3 for a gas-to be treated. and removable heads 4 and'5, the latter of which may be of a simple screw-cap type, and the former preferably held in a manner to allow quick removal as for instance by bolts 6. Extending through the head 4 is a stem 7 which is arranged for longitudinal movement, as for instance by being screw-threaded and having *a coacting nut 8 with suitable means for turning, conveniently a hand-wheel 9. The nut 8 v is preferably journaled in a yoke 10 upon the head or capable of being held .in fixed rela-.

tion thereto. The stem 7. carries a plunger 11 and in order to allow passage of gas, this may be perforated and it is further desirable I to apply a facing thereto of wire mesh material 12, the plunger and facing being held to the stem by a nut or the like 13'. Near the lower end of the casing and above the gas nlet is a grating 14. which may likewise have a facing of wire mesh material. A drain pipe 15 with control valve 16 is applied at the lower end.

In use, the device is filled with calcium chloride or the like, and gas being admitted at inlet 2 passes up through the moisture-absorbing mass and discharges at outlet 3 being taken off through suitable containers as desired. As the moisture-absorbent material takes up proportionally more moisture at the 1nlet end, it begins to deliquesce and soften and flow down into the space below from which it may be drawn off by valve 16. In order to make up for the portion of the moisture-absorbing material which softens from the moisture take-up and flows down from the zone of contact, replenishing charges are supplied from time to time. This is accomplished by stopping the gas flow, and forcing'th'e column of moisture-absorbing material down again against the lower grating 14, a heating agent as steam having been admitted into the jacket 17 surrounding the container. The heating agent softens the moisture-absorbing material contiguous to the wall of the container and thus loosens the column so that upon turning the hand-wheel 9, stem 7 and its plunger can be thrust down, thus pushing the column of calcium chloride again into compact position against the lower grating. The yokev 10, head 4 and plunger 11 are now removed, the screw stem and plunger having preferably been run up to facilitate this, and a charge of calcium chloride is filled into the casing to bring the bulk up again to original proportions. The plunger and head 4 are now replaced and the plunger maybe tightened down to compact the mass conveniently. In this manner by successively pushing the column of moisture-absorbing material down as it is dissolved away at the gas inlet end, replenishing charges may be added as needed to maintain the eifective mass at about its original proportion. Instead of applying the moisture-absorbingmaterial in the manner described, in some cases I contemplate the use of a stack of trays 18 in the casing 1, each tray containing the moisture-absorbent material, such as calcium chloride. The trays are originally placed so as to fill the space in the container, and as the material in the trays at the gas inlet 'end liquefies and runs out into the space below, the empty trays may be withdrawn, one or more as the case may be, through the swing door 19 just above the grating 14. New trays to correspond at the same time may also be introduced through a door 20 at the gas outlet end. These doors 19 and 20 may be conveniently mounted on a hinge 21 at one side and have a take-up swing bolt 22 at the other side by which they may be drawn up tightly against the casing. As in the foregoing form, any adherence of the calcium chloride to the container walls may be overcome to allow movement of the column of trays, by passing steam into the jacket 17, but with this form of device resort to heating is not ordinarily required,

and the jacket may be omitted.

For very humid gases the deliquescing salt flowing down into the space at the gas inlet end may be made to furnish still further service if a pervious filling 23 be provided, such for instance as stone, coke, Raschig rings, metallic screen, or excelsior, etc. This allows of a good surface exposure of the fluid moisture-absorbing material and at the same time suflicient passageway for the gas is allowed.

In order to quickly cool the mass of calcium chloride or the like after steam has been applied to the jacket 17, it is generally desirable to flood the jacket with cold water.

Other modes of applying the principle of my invention may be employed, change being made as regards the features described, provided the steps or elements stated in any of the following claims or the equivalent of such stated steps or elements be used.

I therefore particularly point out and distinctly claim as my invention 1. In an apparatus for dehumidifying gases, the combination of an elongated casing having an inlet for a gas near one end and an outlet near the other end, a readily removable cover at the gas outlet end, means for progressing charges of solid moistureabsorbing material toward the gas inlet end of the casing, and pervious means for exposmg a solution of moisture-absorbing material to the gas.

2. In an apparatus for dehumidifying gases, the combination of an elongated casing having an inlet for the gas near one end and an outlet near the other end, a readily. removable cover at the gas outlet end, means for progressing charges of a moisture-absorbmg material toward the gas inlet end of the gases, the combination of an elongated casing having an inlet for a gas near one end and an outlet near the other end, a readily removable cover at the gas outlet end, a stem movable through said cover, a plunger-carried by said stem within thecasing, a grating, and a pervious filling between said grating and the gas inlet.

4. In an apparatus for dehumidifying gases, the combination of an elongated casing having an inlet for gas near oneend and an outlet near the other end, a readily removable cover at the gas outlet end, a yoke on said cover, a screw-stem supported by said yoke, a plunger carried by said. stem Within the container, a grating near the gas inlet end of the container, and means for softening moisture-absorbing material adherent to the casing, a drain below said grating.

Signed by me this 20th day of August, 1926.

ALBERT KELVIN SMITH.

casing, a grating, and a pervious filling between said grating and the gas inlet.

3. In an apparatus for dehumidifying 

